Quick Dips

Navy Surveys Fiordland

It's been almost 150 years since HMS Acheron surveyed the waters of Fiordland, and local charts are finally getting an update courtesy of the Royal New Zealand Navy's Hydrographic Surveying Service.

There has been little need for modern charts of the area in recent years, as it has mainly been used by fishermen and a few yachts. Apart from the chart of Doubtful and Thompson Sounds -- surveyed by the RNZN in 1985 --  charts are based upon the 1851 surveys of HMS Acheron with some additional work, such as wire sweeping of the channels in Dusky Sound and check surveys at Milford to ensure navigational safety.

Over the past few years, the number of cruise ships visiting Fiordland has increased dramatically and smaller vessels are offering "eco-tours" and cruises to historic areas in Fiordland. At the start of 1994, the navy's main survey ship, HMNZS Monowai, and two Inshore Survey Craft, Takapu and Tarapunga, began surveying the entire Fiordland area from Puysegur Point in the south to Milford. The initial survey, of Preservation and Chalky Inlets, was completed by Easter and is currently being checked. During winter, the survey vessels left for warmer climes, returning to Fiordland at the start of October.

Monowai will survey Dusky Sound while the ISCs survey Acheron Passage and Breaksea Sound. Charts of offshore areas are often compiled from various sources and much of Fiordland's offshore area to Milford Sound was surveyed by a French research ship, L'Atalante, in late 1993 [see Mapping a Muddy Swath, October]. Monowai has the responsibility for surveying from the coastal margin out to the L'Atalante sounded area, with just the inshore strip being left for the ISCs.